What is the difference between a niche community and a large general one?

Niche and large general communities on Reddit serve fundamentally different purposes and offer distinctly different user experiences, making the choice between them consequential depending on what you are trying to accomplish. A niche community is defined by tight topical focus and typically a smaller membership, usually ranging from a few hundred to tens of thousands of members. The discussions within a niche subreddit are highly specific — a community dedicated to a particular brand of fountain pens, a narrow subgenre of fiction, or a specific city's local politics will discuss those topics with a depth and specificity that a general community about "writing" or "politics" never could. Members of niche communities tend to share a high level of domain knowledge and shared vocabulary, which enables rapid, dense exchanges that skip the basics. Posts that would be considered too obscure for a general community are welcomed and engaged with enthusiastically in the niche space. As observed in r/buildinpublic discussions, a post in a small niche community can remain visible and generate discussion for days, while the same post in a large general subreddit is buried within minutes. A large general community — think r/gaming (millions of members), r/movies, or r/technology — captures a massive audience but necessarily produces content optimized for the broadest appeal. The content that rises to the top tends to be accessible, broadly relatable, and relatively low-depth. Memes, news items, and general discussion questions consistently outperform technical deep-dives because the audience has highly varied backgrounds. The upside of large communities is exposure and diversity of perspective; the downside is that they rarely satisfy users looking for sophisticated conversation within a specific domain. Most experienced Reddit users maintain subscriptions to both — large communities for cultural participation and niche ones for genuine expertise exchange.